/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Diagnostics;
using System.Collections;
using System.Text;
using System.IO;
using PdfSharp.Internal;
using PdfSharp.Pdf.IO;

namespace PdfSharp.Pdf
{
  /// <summary>
  /// Represents a PDF name value.
  /// </summary>
  [DebuggerDisplay("({Value})")]
  public sealed class PdfName : PdfItem
  {
    /// <summary>
    /// Initializes a new instance of the <see cref="PdfName"/> class.
    /// </summary>
    public PdfName()
    {
      this.value = "/";  // Empty name.
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="PdfName"/> class.
    /// </summary>
    public PdfName(string value)
    {
      if (value == null)
        throw new ArgumentNullException("value");
      if (value.Length == 0 || value[0] != '/')
        throw new ArgumentException(PSSR.NameMustStartWithSlash);

      this.value = value;
    }

    /// <summary>
    /// Determines whether the specified object is equal to this name.
    /// </summary>
    public override bool Equals(object obj)
    {
      return this.value.Equals(obj);
    }

    /// <summary>
    /// Returns the hash code for this instance.
    /// </summary>
    public override int GetHashCode()
    {
      return this.value.GetHashCode();
    }

    /// <summary>
    /// Gets the name as a string.
    /// </summary>
    public string Value
    {
      // This class must behave like a value type. Therefore it cannot be changed (like System.String).
      get { return this.value; }
    }
    string value;

    /// <summary>
    /// Returns the name. The string always begins with a slash.
    /// </summary>
    public override string ToString()
    {
      return this.value;
    }

    /// <summary>
    /// Determines whether the specified name and string are equal.
    /// </summary>
    public static bool operator ==(PdfName name, string str)
    {
      return name.value == str;
    }

    /// <summary>
    /// Determines whether the specified name and string are not equal.
    /// </summary>
    public static bool operator !=(PdfName name, string str)
    {
      return name.value != str;
    }

#if leads_to_ambiguity
    public static bool operator ==(string str, PdfName name)
    {
      return str == name.value;
    }

    public static bool operator !=(string str, PdfName name)
    {
      return str == name.value;
    }

    public static bool operator ==(PdfName name1, PdfName name2)
    {
      return name1.value == name2.value;
    }

    public static bool operator !=(PdfName name1, PdfName name2)
    {
      return name1.value != name2.value;
    }
#endif

    /// <summary>
    /// Represents the empty name.
    /// </summary>
    public static readonly PdfName Empty = new PdfName("/");

    /// <summary>
    /// Writes the name including the leading slash.
    /// </summary>
    internal override void WriteObject(PdfWriter writer)
    {
      // TODO: what if unicode character are part of the name? 
      writer.Write(this);
    }

    /// <summary>
    /// Gets the comparer for this type.
    /// </summary>
    public static PdfXNameComparer Comparer
    {
      get { return new PdfXNameComparer(); }
    }

    /// <summary>
    /// Implements a comparer that compares PdfName objects.
    /// </summary>
    public class PdfXNameComparer : IComparer
    {
      /// <summary>
      /// Compares two objects and returns a value indicating whether one is less than, equal to, or greater than the other.
      /// </summary>
      /// <param name="x">The first object to compare.</param>
      /// <param name="y">The second object to compare.</param>
      public int Compare(object x, object y)
      {
        PdfName l = x as PdfName;
        PdfName r = y as PdfName;
        if (l != null)
        {
          if (r != null)
            return l.value.CompareTo(r.value);
          else
            return -1;
        }
        else if (r != null)
          return 1;
        else
          return 0;
      }
    }
  }
}
